Page 160 of 264

Check to make sure that the axle mounting U-bolt nuts, attaching or
mounting bolts and nuts are securely tightened. Regularly check front
axle for damage, binding, worn parts and adequate lubrication.
At regular intervals, or during other scheduled maintenance, (tire
rotation/service, wheel bearing service, alignment, etc.) the kingpins
should be checked for excessive wear. Refer to the service manual for
proper procedures.
Toe-in setting - general inspection
Inspecting steer axle tires in the first 4,800–16,000 service km
(3,000–10,000 service miles) will generally show if tires are wearing
normally.
Rapid outside shoulder wear on both tires indicates too much toe-in.
Rapid inside shoulder wear on both tires indicates too much toe-out. In
P&D-type service, which includes school buses, left-to-right steer tire
tread life differentials up to 40% can be observed depending on routes
and other variables.
Follow the tire manufacturer’s recommended cold inflation pressure for
the tire size, load range (ply rating) and steer axle loading typical for
their operation (each steer axle tire will equal
1⁄2steer axle loading).
Special applications may warrant a setting based on past experience with
the type of tire operating loads and conditions. Radial tires are more
sensitive to toe-in setting than bias ply tires. While not insensitive to
vehicle alignment, fine tuning school bus alignment to line-haul truck
standards will not drastically improve tire tread life.
It is essential that correct toe-in and tire pressure be maintained for
optimum tire wear.
Rear axle - general inspection
Check to make sure that the axle mounting U-bolts, attaching or
mounting bolts and nuts are securely tightened. Refer toU-bolt nut
torque chartin this chapter. Regularly check the rear axle for damaged,
binding or worn parts.
NoSpin Detroit Locker positive locking differential
Vehicle equipped with this type differential have the operator’s manual
supplied with the vehicle. Refer to this manual for maintenance checks.
Brake system - general inspection
Your vehicle is equipped with non-asbestos brake linings. However,
exposure to excessive amounts of brake material (whether asbestos or
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
160
Page 203 of 264

Prior to re-installing rear aluminum hub-piloted wheels, clean each wheel
locator pad on the hub from all dirt, rust and foreign material. Apply a
light coat of chassis grease, never-seize or disc brake corrosion control
grease, only to the wheel locator pad.
When installing the tire and rim assembly on disc-brake equipped axles,
make sure the tire valve stem clears the brake caliper. The use of a tire
manufacturer’s stem forming tool is the only acceptable method of
obtaining clearance when necessary.
Note:Always observe the following instructions:
•Always loosen rim clamps before complete removal of nut from stud
(cast spoke wheels). With loosened nuts on stud, strike clamps with a
heavy hammer and be sure each clamp is loose.
•Always deflate tires completely before removing locks or side rings.
•Always inflate tires in a safety cage.
•Never mix rim side rings or lock rings of different types,
manufacturers or sizes.
•Never use cracked, bent or badly rusted parts.
•Never re-inflate flat tires on-vehicle; use the spare tire.
•Never add air until each side ring or lock ring is fully seated.
•Never hammer side ring or lock ring on a partially- or fully-inflated
tire.
Failure to follow these instructions could result in property
damage, personal injury or death
Proper torque
It is important to tighten and maintain wheel and rim mounting nuts to
the proper torque. Loose nuts or over-tightened nuts can lead to
premature wear and possible failure of the wheel and/or mounting
hardware.
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
203
Page 205 of 264

TIRE/WHEEL RIM SELECTION AND INFLATION PRESSURES
Tire sizeLoad
rangeApproved
rim widthsAxle capacity
Front - kg
(lbs.)/kPa (psi)Rear - kg
(lbs.)/kPa (psi)
225/70R19.5 F 6.00, 6.753302 (7280) /
655 (95)6196 (13660) /
655 (95)
245/70R19.5 F 6.75, 7.503701 (8160) /
586 (85)7031 (15500) /
586 (85)
245/70R19.5 G 6.75, 7.504123 (9090) /
690 (100)7938 (17500) /
690 (100)
265/70R19/5 G 7.50, 8.254858 (10710) /
827 (120)9199 (20280) /
827 (120)
9R22.5 F 6.75, 7.504082 (9000) /
724 (105)7167 (15800) /
655 (95)
10R22.5 F 6.75, 7.504672 (10300) /
690 (100)8845 (19500) /
690 (100)
10R22.5 G 6.75, 7.505153 (11360) /
793 (115)9526 (21000) /
793 (115)
11R22.5 G 7.50, 8.255602 (12350) /
724 (105)10433 (23000) /
724 (105)
11R22.5 H 7.50, 8.255997 (13220) /
827 (120)10524 (23200) /
758 (110)
12R22.5 H 8.25, 9.006704 (14780) /
827 (120)12247 (27000) /
827 (120)
245/75R22.5 G 6.75, 7.504241 (9350) /
758 (110)8002 (17640) /
758 (110)
255/70R22.5 H6.75, 7.50,
8.254999 (11020) /
793 (115)9199 (20280) /
793 (115)
265/75R22.5 G 7.50, 8.254722 (10410) /
758 (110)8718 (19220) /
690 (100)
275/70R22.5 H 7.50, 8.255997 (13220) /
862 (125)11204 (24700) /
862 (125)
275/80R22.5 G 7.50, 8.255602 (12350) /
758 (110)10297 (22700) /
758 (110)
295/75R22.5 G 8.25, 9.005602 (12350) /
758 (110)10297 (22700) /
690 (100)
295/80R22.5 H 8.25, 9.006704 (14780) /
793 (115)11993 (26440) /
793 (115)
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
205